Electric attachment plug



y 1931. B. P. MCKINLEY 1,804,020

ELECTRIC ATTACHMENT PLUG Filed May 19, 1927- B1 114 if M2 3513 7113flame/1;;

Patented May 5, 1931 UNITED STATES PATENT erricir;

BENJAMIN P. MCKINLEY, OF BRIDG-EPORT, CONNECTICUT, ASSIGNOR TO THEBRYANT ELECTRIC COIEPANY, A CORPORATION OF CONNECTICUT ELECTRICATTAOHFIENT PLUG Application filed May 19, 1827.

This invention relates to separable electric attachment plugs, whereinone of the members is provided with contact making blades arranged forthe connection of elec tric conductors, and the other plug memberadapted for insertion in a lamp socket arranged with contact terminalsfor electrical connection with the shell and end contact terminals ofthe socket and for the insertion therein of the contact making blades tomake electrical connection with contact members therein in electricalconnection with the contactterminals of said plug, and to which latterplug member the present invention particularly relates. This form ofplug is made of molded insulating material with the contact memberscarried thereby in insulated relation to each other, and it is theobject of the invention to make a separable attachmentplug member ofthis character of molded insulator material of the kind commerciallyknown as bakelite, condensite or the like which is expensive, to providean attachment plug member of improved construction and arrangementwhereby a minimum amount of insulating material is required, and whichmay be readily and quickly assembled thus reducing the cost thereof. andto provide a plug which is novel, durable and eflicient in use.

In the drawings accompanying and forming a part of this specificationthere is illustrated an embodiment of the invention in which Figure 1 isa side elevation of my improved separable plug member and showing theother plug member in dotted lines in relation thereto.

Figure 2 is a longitudinal sectional view and showing the other plugmember in dotted lines in separated relation thereto.

Figure 3 is an end elevation of the plug looking at the left of Figure2.

Figure 4 is a perspective view of a cupped member constituting a part ofthe plug and looking at the interior thereof.

Figure 5 is a perspective view of another cupped member constitutinganother part of the plug looking at the interior thereof.

Figure 6 is a perspective view looking at Serial No. 192,507.

the side and one end of a contact shell forming a part of the plugmember.

Figures 7, 8 and 9 are perspective views of Contact making terminals ofthe plug mem ber.

Figure 10 is a view similar to Figure 2 and showing the other plugmember in operative relation thereto.

Figure 11 is a side elevation of the cupped member shown in Figure 4 andcontact making terminal shown in Figure 8 carried thereby and showingthe same assembled.

Figure 12 is a side elevation of the cupped member, partly in section,and contact making terminal shown in Figure 11 and showing the sameassembled.

Figure 13 is a view similar to Figure 12 showing the shell contactassembled in relation thereto.

Figure 14 is an end elevation looking at the right of Figure 13 with theshell contact in section, and

Figure 15 is a side elevation of the cupped member of the plug with thecontact making terminals in disassembled relation and pre paratory touniting the two members ofthe plug.

The embodiment of the invention illustrated comprises a pair of membersA and B of cup shape of molded insulating material, such as bakelite,condensite and the like adapted for longitudinal mating connection, forwhich purpose the member A is arranged with diametrically opposite lugs16 extend ing from the end of the wall, and the member B is arrangedwith diametrically opposite recesses 17 for engagement of the lugs 16 tonot only serve as guide means in assembling the members but also to holdthe same against rotary displacement relative to each other. The memberA has an annular enlargement 18 with the periphery serrated or knurledto serve as a finger grip to facilitate connecting the plug with andseparating the same from the usual companion plug C carrying contactmaking blades 19 adapted for connection of electric conductors 20.

The shell A has a hub 21 centrally therein with one end of a post 22 ofconductor material embedded therein, or molded therein,

when said member is formed, the post being arranged with a head at theend and an annular enlargement, as at 23, at the end embedded in thematerial of the hub 21 to prevent longitudinal displacement thereof fromthe hub, the opposite end having a bore 24 therein and being of a lengthto extend through an opening 25 centrally in the mem ber B when inmating relation with the member A, the members being secured into anitary structure by upsetting laterally the extremity of the postforming the wall of the bore, as shown in Figures 2 and 10, and saidoffset portion constituting the center contact terminal of the plug. Toreinforce the side wall of the shell ribs 26 are arranged atdiametrically opposite sides of the hub to extend between the hub andmember wall. The end or bottom wall of the member is arranged with apair of openings 27 at diametrically opposite sides of the hub for theinsertion of the contact blades 19 of the plug C to serve as guidestherefor and the hub serving as a spacing and insulating abutment forsaid blade contacts when they are inserted into the openings. Ridges 39in the interior of the cupped member A extend at right angles to the rib26 at the opposite sides of the accesses 27.

The plug member is arranged with a contact terminal shell comprising athreaded metal sleeve 28 to encircle one of the insulator members, inthe present instance the member B, said contact member having one endflanged inwardly, as at 29, to be engaged between the mating edges ofthe members A and B when united, said flange having diametricallycut-out portions to clear the lugs 16 and a portion 31 cut outintermediate and of greater extent than the portions 30 for a purpose tobe hereinafter described.

To electrically connect the blade contacts 19 of the plug member C withthe conductor post and shell contact 28 when said parts are insertedinto the openings 27 contact making fingers 32, 33 (Figures 8 and 9) areprovided and electrically connected with said conductor post and shellcontact. The contact finger 32 comprises a strip of resilient metal,preferably copper edge wise stiff and laterally yielding or resilient,one end 34 of which is bent at a right angle and perforated, as at 35,for engagement on the reduced end of and in electrical connection withthe conductor post 22. The perforation is of slightly less diameter thanthe reduced end of the post and to permit of the ready engagement of thesame upon the post slits are cut into the wall of the perforation andinto the metal about the perforation providing yielding tongues whichserve to hold the contact finger on the post in assembling. The fingerisengaged upon the post in abutting relation to a shoulder formed at thejuncture of the reduced portion with the body of the post, which isarranged so that the bent portion 24 of the contact finger will engagein a transverse recess in the inner surface of the end wall of themember B when assembled and thus hold. the contactfinger against rotarymovement on the post. The extremity of the bent portion is flaredslightly laterally for engagement with the bottom of the recess 26 toseat the contact finger on the post and also exert a lateral force onthe body portion to position the same contiguous to the wall of themembers. The opposite end portion is bent upon itself, as at 37, so thatit projects at an angle to the main portion of the contact finger andobliquely across an opening 27, and having a pressed out nib 38 to enteror snap into cavities or perforations in the contact blades of plugmember C. The portion of the finger at the juncture of the bent end 37with the main portion is adapted to be engaged and alined between a pairof the parallel ridges 39 at opposite ends of an opening 27 to preventlateral displacement of the contact finger relative to the opening.

The other contact finger 33 has one end portion 42 laterally offset, asat 40, for engagement between the shell contact 28 and cupped member Bat the cut out portion 31 of the flange of the shell contact formounting of the contact finger 33 on said cupped member B in electricalconnection with the contact shell and the main portion of the fingerlying in contiguous relation to the inner surface of the wall of memberA, as clearly shown in Figures 2 and 10, the opposite end being bentupon itself, as at 43, with the portion of the finger at the uncture ofthe bend seated and alined between a pair of the ridges 39 at the outerside of an opening 27 with the bent end portion 43 extend ing at anangle to the main portion of the contact finger and obliquely across anopening 27, and has a pressed out nib 44 to enter or snap into a cavityor perforation of the contact blades of the plug C r In the assemblingof the plug the contact member 32 is engaged 'upon the conductor post22. The contact finger is arranged on the cupped member B with theoffset portion 40 seated in a recess 41. The contact shell 28 is thenpositioned relative to the member A by positioning the member flangeagainst the end of the shell with the lugs 16 engaging the cut-outportion 30 in the shell flange and held in position by one hand, whenthe other member B with the contact finger held in position thereon isinserted into the contact shell 28; or if desired after the contactfinger 34 has been assembled on the conductor post, the contact finger33 inserted into the shell recess 41 and the contact member 28 engagedupon the shell B, when said contact shell and cupped member B may bepositioned in mating relation to the memher A. After the members havebeen assembled in mating relation they are secured together in a unitarystructure by upsetting laterally the extremity of the wall of the borein the end of the conductor post, said offset portion constituting anend contact of the plug.

It will be obvious that modifications may be made in construction andarrangement of parts, and that portions of the invention may be usedwithout others and come within the scope of the invention.

Having thus described my invention, 1 claim:

1. In an attachment plug, a cupped member of insulator material having acontact member carrying hub arranged centrally therein and openingsthrough the end wall at oppositesides of the hub with apair of parallelridges at the opposite sides of the openings to serve as contact memberalining guides in the cupped member relative to said openlngs.

2. In an attachment plug, a cupped member of molded insulator materialarranged with a hub centrally within said member and having openingstherethrough at opposite sides of the hub, a contact member molded inand extending beyond the end of the hub, reinforcing ribs atdiametrically opposite sides of the hub and extending between the huband cup wall, a pair of parallel ridges extending at a right angle tothe ribs at opposite sides of the openings to serve as contact engagingand alining seats in the cupped member relative to said openings.

3. In an attachment plug, a cupped member of molded insulator materialarranged with a hub centrally within the same and having openingstherethrough at opposite sides of the hub, and contact engaging andalining seats in the cupped member relative to the openings, a contactterminal post molded in and extending beyond the hub to constitute theend contact of the plug, and

a contact member embodying a body portion having one end extended at aright angle thereto and perforated for engagement on and electricalconnection with the post with the opposite end folded upon itself toextend at an angle to the body and the contact member at the foldengaging in a contact alining seat with the folded end diverging upwardtherefrom and intersecting an opening.

at. In an attachment plug, a pair of cup shaped members of insulatormaterial arranged for mating connection to form easing with a chambertherein entirely enclosed by the members, one insulator member having aconductor post cent-rally embedded therein and projecting therefromthrough a central opening in the other insulator member and adapted forsecuring the insulator members together into a unitary structure and toserve as a center contact for the plug, and the other insulator memberhaving diametrically oppositely arranged openings therethrough to thecasing member, a shell contact encircling the other insulator memberflanged inwardly at one end for engagement and clamped between themating edges of the insulator members to mount said contact shell uponthe plug when the insulator members are united, and a pair of yieldingcontact fingers within the casing chamber in alinement with the openingslo cated in the one insulator member, with one contact finger carried byand in electrical connection with the'conductor post and the othercontact finger in electrical connection with the shell contact.

5. A separable attachment plug member as claimed in claim 4, wherein theinsulator members and contact shell are arranged with parts tointer-engage to maintain the same in predetermined relation, one contactfinger comprises a strip of metal having one end bent at a right angleto the body portion and perforated for the engagement on an electricalconnection with the post contact, the body thereof being arranged to liecontiguous to the inner wall of the insulator members and having theopposite end folded upon itself to extend obliquely across an opening,and the other contact finger comprising a strip of resilient metalhaving one end portion offset and engaged between the contact shell andone cupped member with the body portion to lie contiguous to the innerwall of the insulator shells and having the opposite end portion foldedupon itself to extend obliquely across the other opening. V

6. A separable attachment plug as claimed in claim 4, wherein theinsulator members and contact shell are arranged with parts tointerengage to maintain the same in predetermined relation, and the onecontact finger comprises a strip of metal having one end bent at a rightangle to the body portion and perforated for the engagement on andelectrical connection with the post contact, the body thereof beingarranged to lie contiguous to the inner wall of the insulator membersand having the opposite end folded upon itself to extend obliquelyacross an opening, and the other contact finger comprising a strip ofresilient metal having one end portion offset and engaged between .thecontact shell and one insulator member with the body portion to liecontiguous to the inner wall of the insulator members and hav' ing theopposite end portion folded upon itself to extend obliquely across theother opening, and one insulator member is arranged with parallel ridgesat opposite sides of the openings for formingseats for the engagement ofthe folded portion of the contact fingers to aline said fingers relativeto the openings.

7 In an attachment plug, a pair of cup shaped members in insulatormaterial arranged for longitudinal mating connection and form a casinghaving a chamber therein and one member having a central openingtherethrough, a post of conducting material carried centrally in theother member of a length to be extended through the central opening inthe one member when the members are connected, said post being adaptedto secure the members into a unitary structure and serve as a centercontact terminal of the plug, the post carrying member being arrangedwith openings to the casing chamber at diametrically opposite sides ofthe post, a shell contact encircling the member arranged with thecentral opening, and a pair of contact fingers carried within the casingchamber in alinement with the openings, one in electrical connectionwith the post contact and the other in electrical connection with theshell contact.

8. In an attachment plug,a cupped member, a metallic shell contactencircling said cupped member and flanged inwardly at one end over theedge of the wall of said member, and a contact member of resilientmaterial having one end offset laterally and the extended end engagedbetween the body portions of the shell contact and cupped member withthe offset in abutting relation to the edge of the cupped member formounting said resilient contact member on the cupped member inelectrical connection with the shell contact.

9. A separable attachment plug member as claimed in claim 4, wherein theinsulator members and contact shell are arranged with parts tointerengage to maintain the same in predetermined relation, one contactfinger comprises a strip of resilient material having one end bent at aright angle to the main portion and perforated for engagement on andelectrical connection with the post contact and the other end obliquelycrossing an opening, and the other contact finger comprising a strip ofresilient material having one end portion offset and the extendedextremity thereof engaged between the contact shell and one cuppedmember and the other end extending obliquely across the other opening.

10. An attachment plug part comprising a cup member of molded insulatormaterial having a hub integral therewith fixed centrally within andextending axially from the end wall of said cup member, a contact mem;ber molded in and extended axially from said hub, and openings throughsaid end wall at diametrically opposite sides of said hub.

Signed at Bridgeport, in the county of Fairfield and State ofConnecticut this 17th day of May. 1927.

BENJAMIN P. MGKINLEY.

